> Can you please specify whether you use (paid) GPT-4?
Paid.
> Would you kindly provide links to a few examples of very fundamental things incorrect?
No, definitely not.
> I notice very rarely that it hallucinates.
Unsure of what "hallucinates" means in this case. Some examples of things I've used it for: docker configuration, small blocks of code, generating a cover letter, proofreading a document, YAML validation, questions about various software SDKs. The outcome is usually somewhere on the spectrum of "not even close/not even valid output" to "kind of close but not close enough to warrant a paid service". When I ask for a simple paragraph and I get a response that isn't grammatically correct/doesn't include punctuation, I'm not sure what I'm paying for.